Jonah Lomu is likely to have died from a blood clot which formed during a long-haul flight from Dubai to New Zealand, one of his medics has admitted.

The former All Blacks doctor John Mayhew, who announced the death of the former wing last week and helped to treat Lomu's chronic kidney disease, believes his condition made him vulnerable.

“He returned from the UK via Dubai and appeared to be in good health before he died,” Mayhew told BBC 5 Live on Sunday.

“We think the most likely cause was a clot on the lung which can be a complication of long distance travel. Jonah was at greater risk of that happening because of his renal condition.

“I think it was instantaneous. He was unaware of what had happened,” Mayhew added. “It’s just one of those tragic complications that can occur in people with chronic renal conditions.”

The New Zealand prime minister John Key announced on Monday that a public memorial service for Lomu is to be held on 30 November in Auckland at Eden Park stadium. A private funeral for the All Blacks favourite takes place the following day. Key wrote on his official website: "Jonah touched people's lives across the country and around the world.

“This service will be open to all members of the public who want to remember the significant contribution Jonah made, not only to rugby here and overseas, but also to the wider community through his work with charities such as UNICEF and Kidney Kids NZ.

“The service will be a celebration of Jonah’s life and I expect a large number of people will want to be there.”

(Guardian service)